Comparison of the stability of different le fort i osteotomy technics on maxillary advancement methods

In our study, the effect of M-shaped osteotomy technique, which is a modification of the technique of Le Fort I osteotomy, which was used to activate the upper jaw in orthognathic surgery, was investigated for postoperative relapse prevention activity. Finite Elemet Analysis study, whose reliability is supported by the literature was used to investigate this study. It is aimed to determined the maximum stress areas with two different osteotomy techniques that will occur after the downward positioning process which is the most unstable movement in maxilla, the stress areas formed in the fixation system and the stability and relapse problems that may occur as a result. In our study, the computed tomographic image of a patient was analyzed using the Finite Element Analysis method. After the maxillary advancement and downward positioning performed with M-shaped osteotomy technique with conventional Le Fort I osteotomy technique on the three-dimensional study model, the maximum stress areas occurring in the bone and plaque systems were evaluated for stability and relapse. Our study consist of 6 groups. The maxillary advancement in the groups was the same and 5 mm in all, and the down positioning was determined as 3 mm and 5 mm. After conventional Le Fort I osteotomy, iliac graft was used between the segments. The reason for the use of iliac graft as interpositional graft is to report iliac graft as a gold standard in the literature. In the control group, conventional Le Fort I osteotomy was performed but graft was not used. After osteotomy, 4-hole L shaped plate and 5 mm screws were fixed. As a result of our study, it was concluded that compared to the conventional Le Fort I osteotomy method, M-shaped osteotomy method was less stressed in terms of stress parameters.